Reference

HTTP MCP server

The streamable HTTP transport for remote MCP clients: endpoints, CORS, and limits.

http.js (source) exposes the same two MCP tools over a stateless, CORS-enabled streamable HTTP transport, for MCP clients that cannot spawn a local stdio process (ChatGPT connectors, Claude custom connectors, and similar).

Endpoints

MethodPathBehavior
GET/Plain-text landing page with client config and tool list
GET/healthReturns ok
POST/mcp (or /)JSON-RPC request or batch; returns the JSON-RPC response
OPTIONSanyCORS preflight, 204

Behaviors and limits

  • Batching: a JSON array of requests is processed concurrently and answered as an array; notification-only input returns 202 with an empty body.
  • Body cap: requests over 1 MB are rejected with a JSON-RPC error and 413.
  • CORS: Access-Control-Allow-Origin: * plus the MCP session headers, so browser-based clients work out of the box.
  • Port: PORT env var, default 8080; a Dockerfile ships in the repo for one-command container deploys (Dockerfile).

Client configuration:

{ "mcpServers": { "ai-readiness": { "url": "https://<host>/mcp" } } }
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